Expression of NIS Protein and mRNA in Thyroid Tumors

Significant Intracellular NIS Protein Associated With Low Levels of NIS Messenger RNA in Malignant Thyroid Tumors

The uptake of iodide by thyroid cells requires the expression of sodium iodide symporter (NIS). Thyroid benign and malignant tumors have low iodide uptake activity. Previous studies of NIS expression with RT-PCR and immunohistochemistry showed divergent data. NIS protein was overexpressed in thyroid cancer. The aim of this study was to investigate the NIS transcript levels and its presence and localization in 30 samples of thyroid tumors (14 benign and 16 malignant) and in their surrounding non-tumoral tissues (NT), by real time RT-PCR and immunohistochemistry, respectively. Our results revealed lower gene expression in 78.6% of the benign tumors and 100% of the carcinomas when compared with the NT samples, using GHPDH as a housekeeping gene. Immunohistochemical staining revealed presence of NIS protein in 100% of the non-tumoral samples, 100% of the benign tumors and 93.75% of the malignant tumors. NIS protein was identified at basolateral membrane in 23.3% of non-tumoral samples, 14.3% of benign and 12.5% of malignant tumors. Stronger cytoplasmatic immunostaining of NIS protein was detected in 64.3% of benign tumors and in 87.5% of malignant tumors when compared to NT. Association between low gene expression and strong cytoplasmatic immunostaining was found in 50% of benign tumors and 87.5% of malignant tumors. We concluded that the reduced NIS gene expression in thyroid tumors associated with strong intracytoplasmatic staining may be due to its incapacity to migrate to cellular membrane.

Study Overview

• Status: Completed
• Conditions: Tumors

Detailed Description

The aim of this study was to quantify NIS transcript levels by real time PCR and to determine the presence and cellular localization of NIS protein by immunohistochemistry, in benign and malignant thyroid tumor cells and to compare with their paired surrounding non-tumoral cell. NIS expression was also compared to that of the TSHR

• Study Type: Observational
• Enrollment: 30

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years to 80 years (Adult, Older Adult)
• Accepts Healthy Volunteers: No
• Genders Eligible for Study: All

Description

Inclusion Criteria:

• PAtients with thyroid tumors undergoing surgery for total or partial thyroidectomy

Exclusion Criteria:

• Pregnancy

Study Plan

How is the study designed?

Collaborators and Investigators

• Sponsor: University of Sao Paulo
• Collaborators: Fundação de Amparo à Pesquisa do Estado de São Paulo
• Investigators: Principal Investigator: Ana K Sodré, University of Sao Paulo; Study Director: Rosalinda Y Camargo, University of Sao Paulo

Publications and helpful links

General Publications

• Saito T, Endo T, Kawaguchi A, Ikeda M, Katoh R, Kawaoi A, Muramatsu A, Onaya T. Increased expression of the sodium/iodide symporter in papillary thyroid carcinomas. J Clin Invest. 1998 Apr 1;101(7):1296-300. doi: 10.1172/JCI1259.

Study record dates

Study Major Dates

• Study Start: April 1, 2002
• Study Completion (Actual): October 1, 2006

Study Registration Dates

• First Submitted: April 10, 2007
• First Submitted That Met QC Criteria: April 10, 2007
• First Posted (Estimate): April 12, 2007

Study Record Updates

• Last Update Posted (Estimate): April 12, 2007
• Last Update Submitted That Met QC Criteria: April 10, 2007
• Last Verified: April 1, 2007

More Information

Terms related to this study

• Keywords: NIS; thyroid cancer; Iodine uptake; thyroid adenoma; expression
• Additional Relevant MeSH Terms: Neoplasms; Neoplasms by Site; Endocrine System Diseases; Endocrine Gland Neoplasms; Head and Neck Neoplasms; Thyroid Diseases; Thyroid Neoplasms
• Other Study ID Numbers: PRN736/02